Acute levodopa intake and associated cortisol decrease in patients with Parkinson disease.

Area of Science:

• Neuroendocrinology
• Neuropharmacology
• Movement Disorders

Background:

• Levodopa is a primary treatment for Parkinson disease (PD) motor symptoms.
• Previous research suggests levodopa affects cortisol and serotonin levels.
• The precise neurobiological mechanisms linking levodopa, cortisol, and PD progression require further investigation.

Purpose of the Study:

• To investigate the effect of levodopa administration on plasma cortisol concentrations in Parkinson disease patients.
• To explore the relationship between cortisol levels, PD severity, and levodopa treatment.
• To hypothesize the neurobiological pathways mediating levodopa-induced cortisol changes.

Main Methods:

• A cohort of 32 Parkinson disease patients received soluble levodopa/benserazide (200 mg).
• Plasma cortisol concentrations were measured at multiple time points before and up to 150 minutes after administration.
• Correlation analysis was performed between cortisol levels, PD stage, and Unified Parkinson Disease Rating Scale (UPDRS) scores.

Main Results:

• Cortisol levels significantly decreased post-levodopa administration.
• The cortisol reduction was more pronounced in patients with advanced PD compared to early-stage patients.
• A significant inverse correlation was observed between cortisol levels and UPDRS total scores.

Conclusions:

• Short-term levodopa administration reduces plasma cortisol levels in Parkinson disease patients.
• The effect is more significant in advanced PD stages, suggesting a link to disease progression.
• Hypothesized mechanism involves levodopa's conversion to dopamine in serotonin-producing neurons, impacting the HPA axis and cortisol release.